FORMATION OF INTERFACIAL PHASES BETWEEN SILICA AND UNDOPED OR ANTIMONY-DOPED SILICON MELTS

Interfacial phase formation during dissolution of silica in undoped or Sb-doped Si melts were studied using electron probe microanalysis. Re sults showed that reaction between silica and the Si melt depended on the Sb concentration in the Si melt. A foil-shaped interfacial phase w ith a composition about SiO1.8 appeared between the Si melt and the wa ll of the silica ampoule when the Sb concentration was less than 0.5 a t. %. However, the interfacial phase changed both in shape and composi tion when the Sb concentration was higher. The shape of the interfacia l phase became dendritic and the composition was SiO2 when the Sb conc entration was in the range from 0.5 to 2.0 at. %. The interfacial phas e disappeared when the Sb concentration was higher than 2.0 at. %.